This paper presents a multiagent recommendation system (RecMAS) able to coordinate the interactions between a user agent (AgUser) and a set of commercial agents (AgComs).It provides a useful service for monitoring changes in the AgUser's beliefs and decisions based on two parameters: (i) the strength of its own beliefs and (ii) the strength of the AgComs' suggestions.The system was used to test several commercial activities in a shopping centre where the AgComs provided information to an AgUser operating in a wireless device (PDA, mobile phone, etc.) used by the client.The AgUser received messages adapted to the preferences of the client.Using a theoretical model and a set of simulation experiments, several commercial strategies were obtained.This paper concludes with a presentation of a prototype in a real shopping centre.